Here is a patch that adds a few (for me) very important enhancements:

1. If a menu item has 'class="open"' or 'class="closed"' set, treeview will no longer let the persistent state from a cookie override and erroneously close or open something that should not be closed or open.

2. Treeviews cookies would not set a path, and that results in the cookie path defaulting to whatever path the browser currently was on. This screws up the persistence when you need it to go to different paths on your site. I have added the option 'cookiePath' to treeview, so you can force the path to '/' or whatever other path you might want to solve this issue. I have also made the default option '/'.

3. I have added the option 'cookieExpires' for those of us that wants persistence for longer than just the session. I set this option to default to 0. Personally I set it to 365.